Soil & Water Resources Development and Conservation, Irrigation, Drainage and Allied Subjects (HIGH PRIO) Flashcards
(343 cards)
The recent monsoon rains have posted a nearly uniform rainfall intensity of 30 mm/hr over a 1,500-hectare watershed area in Central Luzon. If the runoff coefficient is 0.15, what is the runoff in m3/sec?
a. 18.75
c. 1.87
b. 187.5
d. 1.875
a. 18.75
Q = CiA
Q = (30 mm/hr)(1500 ha)(10000 m2/ha)(1 hr/3600s)(1m/1000mm)
Ratio of the dry weight of soil particles to the weight of an equal volume of water
a. Particle Density
b. Bulk Density
c. Real specific Density
d. Apparent specific density
c. Real specific Density
A television network is planning to air four 30-minute sitcoms namely: “Mana-Mana”, “Okidoki”, “Tanging Ama” and “Home Along da Sea”. In how many ways can the network arrange these sitcoms in a 7-9 pm time slot if “Mana-Mana” should be aired third?
a. 1
b.2
c.6
d.24
c.6
3! = 6
An artesian well has a diameter of 10 cm. Under steady state condition, what is the expected discharge (lps) if the drawdown is 2.5 m and the radius of influence is 120 m? The aquifer’s hydraulic conductivity and thickness are 75 m/day and 4 m, respectively.
a. 7.01 lps
b. 8.01 lps
c. 9.01 lps
d. 10.01 lps
a. 7.01 lps
Q = 2pikt(deltah)//ln(re/rw)
Q = 2pi(75 m/day)(4 m)(2.5 m)/ln(120m/0.05m)
convert m3/day to lps
For rolling areas and non-uniform distribution of gages, distance factor fixed by location of gages is used for analysis using this method.
a.Inverse Distance Ratio Method
b.Grid-Point Method
c.Isohyetal
d.Thiessen polygon
a.Inverse Distance Ratio Method
What is the soil erosion of 10 T/ha/yr in mm/yr?Assume that the soil bulk density is 1.2 T/m3.
a. 0.083 mm/yr c.0.83 mm/yr
b. 8.33 mm/yr d.80.33 mm/yr
c.0.83 mm/yr
Soil erosion = (10T/ha/yr)/(1.2 T/m3)
convert units
Which among the elements is a major element for plant nutrition?
a. Boron
b. Chlorine
c. Nitrogen
d. Silicon
c. Nitrogen
The process of converting water and carbon dioxide into sugar using chlorophyll and light energy accompanied by the production of oxygen by green plants:
a. respiration
b. oxidation
c. transpiration
d. photosynthesis
d. photosynthesis
An irrigation engineer, in his study, was able to establish that the irrigation requirement of crop XYZ is 6.5 mm/day. If the rootzone depth was estimated at 2 in. On the average, what should be the design discharge of a canal to be able to deliver the 5-day requirement of a 10 ha farm in 24 hours?
a. 31.62 lps
b. 47.62 lps
c. 57.62 lps
d. 37.62 lps
Q = (6.5 mm/day)(5 days)(10 ha)(10000 m2)/(24 hours)
Q = convert L/h to lps
Total water yield from a storm for a given watershed
a. Surface runoff
b. Subsurface runoff
c. Groundwater runoff
d. Runoff volume
a. Surface runoff
The gross application depth is 93mm to irrigate a crop with a crop coefficient of 0.9. The reference crop evapotranspiration is 6mm/day. If the application efficiency is 70%, the irrigation interval is.
a. 10days b.11days c.12days d.13days
c.12days
II = (dnet)/ETc
dnet = dgross x Ea
ETc = ETo x Kc
II = (93 mm x 0.7)/(6 mm/day x 0.9)
II = 12 days
This resembles terracing in that the drainage ditches are constructed around the slope on a uniform grade according to the land topography.
a. Random ditch system
b. Double-main system
c. Interception or cross-slope system
d. Diversion or parallel ditch system
c. Interception or cross-slope system
It is the soil moisture allowable depletion of most crops.
a. 50%
b. 20%
c. 80%
d. 100%
a. 50%
Given the following data:
Evapotranspiration = 5 mm/day,
Percolation = 2mm/day,
Rainfall for November = 200 mm,
Effective rainfall for Nov. = 50%,
Soil Porosity = 60%,
Apparent Specific Gravity = 1.4,
Residual Soil Moisture = 15%,
Rootzone depth = 200mm,
Application efficiency = 75%,
Conveyance efficiency = 80%,
Ave. fraction of area covered = 0.5,
Dependable flow = 4.5 m/sec,
Duration of land soaking = 5 days
16. What is the net land soaking requirement?
a. 78 mm/day c. 15.6 mm/day
b. 7.8 mm/day d. 0.65 mm/day
c. 15.6 mm/day
LSR = (n-(AsxRMC))(DRZ)
LSR = (0.6 - (1.4 x 0.15))(200 mm)
LSR = 78 mm
NetLSR = 78 mm/5 days = 15.6 mm/day
Wherein the surface is rarely wet since the water is supplied from the soil underneath
a. Sprinkler irrigation
b. Sub-irrigation
c. Drip or trickle irrigation
d. Contour-ditch irrigation
b. Sub-irrigation
An internal condition of a seed or bud that prevents its prompt germinating or sprouting under normal growth conditions:
a. dormancy
b. diffusion
c. germination
d. dominant
a. dormancy
The process of moisture lost of plants through the leaves:
a. germination
b. transpiration
c. oxidation
d. flowering
b. transpiration
A natural body composed of a variable mixture of broken and weathered minerals and decaying organic matter and when containing the proper amount of air and water, supplies sustenance and gives mechanical support of plants:
a. fertilizer
b. soil
c. humus
d. mineral
b. soil
A concrete lined canal is to convey water over a distance of 250 m from the well to a tomato farm. Drop in elevation is 0.5 m over the 250 m canal length and roughness coefficient, n, is 0.018. Estimate the bottom width of a rectangular canal with a depth of flowing water of 0.25 m if the hydraulic radius is equal to the area of flow.
a. b = 0.5 m
b. b = 50 m
c. b = 0.25 m
d. b = 25 m
The velocity of water in the canal is
a. 0.62 m/sec
b. 6.2 m/sec
c. 62 m/sec
d. 0.062 m/sec
a. b = 0.5 m
a. 0.62 m/sec
b=2d (most efficient)
A=bd
Then use Manning’s equation to find the velocity.
It involves controlled flooding from field ditches along the contour of the land, which allows the water to flood down the slope between field ditches without employing dikes or other means that guide or restrict its movement.
a.Sprinkler irrigation
b.Sub-irrigation
c.Level-border or basin irrigation
d.Contour-ditch irrigation
d.Contour-ditch irrigation system
The volume of the soil sample during sampling was 85 cc and weight after drying in the area was 130g. The volume weight of the soil is
a. 1.5 g/cc
b. 1.75 g/cc
c. 1/25 g/cc
d. nota
a. 1.5 g/cc
The percentage of moisture by weight of a soil sample of 85 cc with a dry weight of 130 if the weight of the sample before drying was 145 g.
a.12.5% b.10.5% c.9.5% d.11.5%
d.11.5%
MCm = 145-130/130 x 100 = 11.5%
Similar to that of tertiary canals, the main systems (main and secondary canals) also incur losses termed as conveyance losses. Seepage and percolation losses and evaporation along the conveyance canals comprise the conveyance losses.
a. Diversion Water Requirement (DWR)
b. Farm Water Requirement (FWR)
c. Irrigation Water Requirement (IWR)
d. Crop Water Requirement (CWR)
a. Diversion Water Requirement (DWR)
The common name for Capra hircus:
a. sheep b. pig c. mule d. goat
d. goat